Led lighting system and opertaing method for irradiation of plants

ABSTRACT

An LED illumination system is operable to irradiate plant materials with photosynthetically active radiation. A lighting assembly includes a plurality of different LED types. Each LED lamp has a different spectral power matched to an absorption peak of the plant materials. All of the LED lamps of each different lamp type are driven by a different dedicated power source. Each power source can be independently modulated to vary the collective spectral power output of the LED illumination system. The lighting assembly includes fluid conduits disposed proximate to the LED lamps and a cooling fluid is flowed through the fluid conduits to removed thermal energy from the LED lamps.

1.1 COPYRIGHT NOTICE

A portion of the disclosure of this patent document may contain materialthat is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent files or records, but otherwise reserves all copyrightrights whatsoever. The following notice shall apply to this document:Copyright 2016 GS Thermal Solutions.

1.2 BACKGROUND OF THE INVENTION 1.2.1 Field of the Invention

The exemplary, illustrative, technology herein relates to systems, andmethods for irradiating horticultural products using liquid cooled LightEmitting Diode (LED) lighting systems.

1.2.2 The Related Art

Horticultural products are more frequently grown indoors usingartificial lighting. Conventional indoor lighting used to irradiatehorticultural products is provided by High Intensity Discharge (HID)lamps which includes metal halide and high-pressure sodium (HPS) lightbulbs. One problem with the HPS light bulbs is that they operated athigh temperatures and therefore emit high levels of thermal radiationthat tends to excessively heat the indoor space in which they are beingused. Additionally, HPS lamps can generate enough thermal radiation todamage the plants and therefore HPS lamps need to be sufficiently spacedapart from the horticultural products, e.g. by at least 2 feet and insome cases, up to 4 feet (0.3-0.6 Meters) to avoid damaging the plants.

Typically, HPS lamps are housed within a reflective enclosure configuredto reflect and redirect useful radiant energy being emitted by the lamptoward the horticultural products. However, the thermal energy beingemitted by the HPS lamps is absorbed by the reflective enclosure whichleads to a need to cool the reflective enclosure using a forced airflow.As a result, most indoor growing spaces illuminated by HPS lamps areclimate controlled to compensate for the high levels of thermalradiation being generated by operating the HPS lamps. The added cost ofoperating a climate control system just to remove thermal energy emittedby the illumination system is undesirable.

A further problem with HPS light bulbs is the life expectancy.Typically, HPS light bulbs are replaced every six (6) months, and theballast is replaced once per year. The short life expectancy andfrequent replacement of HPS lamps leads to high operating costs andthere is a need in the art to reduce irradiation operating costs byproviding a longer lasting light source.

Another problem with convention HID discharge lamps is that the spectralpower of the emitted radiation is incompatible with the needs of thehorticultural products. HID lamps each have a standard spectral powerthat includes significant radiant energy at wavelengths that provide nouseful benefit to horticultural product growth. This is demonstrated inFIG. 8 which provides a graphical comparison (800) between the relativespectral absorption of plant material vs wavelength of the spectralenergy and the relative spectral power vs wavelength of a conventionalHPS light source.

Photosynthesis relies on pigments (chlorophyll A, chlorophyll B andcarotenoids) to absorb light and transfer energy from the absorbed lightto the plant. The relative amount of light absorbance by chlorophyll A,chlorophyll B and carotenoids vs wavelength is shown in FIG. 8 in thegraphical comparison (800). A first curve, (805) shows the relativeabsorbance of chlorophyll A vs wavelength. The first curve (805) has amajor absorption peak at about 430 nm and another absorption peak atabout 700 nm. A second curve (810) shows the relative absorbance ofchlorophyll B. The second curve (810) has a main absorption peak atabout 460 nm and another absorption peak at about 675 nm. A third curve,(815) shows the relative absorbance of carotenoids vs wavelength. Thethird curve (815) has a main absorption peak ranging between about 450and 520 nm and another absorption peak at about 675 nm coincident withan absorption peak of the second curve (810) at about 675 nm.

Thus, chlorophyll A, chlorophyll B mainly absorbs violet and blue lightat the main absorption peaks and absorb red and deep red light at thesecondary absorption peaks. However, chlorophyll A and chlorophyll Breflect or transmit green and yellow light having a wavelength spectrumin the range of about 550 to 650 nm. The carotenoids mainly absorbindigo and blue light at the main absorption peak between about 450 and520 nm and absorb red light at 675 nm. However, the carotenoids reflector transmit yellow and orange light having a wavelength spectrum betweenabout 550 and 650 nm.

To demonstrate the main drawback of conventional HPS light sources usedto irradiate horticultural products, the relative spectral power vs.wavelength of a conventional HPS light source is plotted in FIG. 8 onthe graphical comparison (800). A fourth curve, (820) shows the relativespectral power vs wavelength of a conventional HPS light source. Thefourth curve (820) has a three strong relative spectral power peaksbetween about 575 and 620 nm with a minor relative spectral power peakbetween about 460 nm and 480 nm. Thus, the majority of the relativespectral power output of a conventional HPS light source is yellow andorange light which is not readily absorbed by any of the three pigmentsresponsible for photosynthesis and is mainly reflected by or transmittedthrough plant materials. To compensate for this major shortcoming of theconventional indoor lighting systems used to illuminate horticulturalproducts, the HPS lamps are operated at very high power levels toirradiate plant material with enough of the spectral power that is in auseful spectral range for plant growth. The only spectral power of theHPS lamps that can be absorbed by plant materials is provided by thethree minor spectral peaks (830) and the tail of the main spectral peak(835). Otherwise, as is demonstrated by FIG. 8, the majority of thespectral power emitted by the HPS light provides no actual benefit tothe plants.

LED lighting systems are known for irradiating plant growth. One suchsystem is disclosed in U.S. Pat. No. 5,012,609 to Ignatuis et al. whichdescribes a plant irradiance system using three different LED lamp typesemitting at three different wavelengths. Another such system isdisclosed in U.S. Pat. No. 7,933,060 to Dubuc which describes a supportstructure for uniform light distribution from LED's.

1.3 DEFINITIONS

The following definitions are used throughout, unless specificallyindicated otherwise:

TERM DEFINITION LED Light emitting diode HID High intensity dischargelighting HPS High pressure sodium light Radiant power Also calledradiant flux is the radiant energy emitted, (in Watts) (W) reflected,transmitted or received, per unit time. In the present invention radiatepower is used to describe the total radiant energy emitted by a LEDlamp. Spectral power Also called spectral flux is the radiant power perunit (in Watts/ frequency or wavelength. nanometer) (W/nm)

1.4 SUMMARY OF THE INVENTION

These and other aspects and advantages will become apparent when theDescription below is read in conjunction with the accompanying Drawings.

The present invention provides a lighting assembly comprising thatincludes at least two and preferably four longitudinal light supportbeams each having a longitudinal length, and each assembled with atleast two transverse end beams. Each of the longitudinal light supportbeams is formed with a base wall having a transverse width and two sidewalls extending from the base wall. The base wall and the two side wallstogether form three sides of a lamp cavity that extends substantiallyalong the entire longitudinal length. The lamp cavity has a rectangularcross-section but may be trapezoidal in order to provide a larger coneangle for light being emitted out of the lamp cavity.

An LED lamp support structure is mounted to the base wall inside thelamp cavity substantially along the entire longitudinal length of eachof the longitudinal light support beams. Each lamp support structureincludes an array of LED lamps mounted to the LED lamp supportstructure. The array of lamps is distributed substantially along theentire longitudinal length of each of the longitudinal light supportbeams. Each array may include a single double or large row of LED lampsspaced apart along the longitudinal length. The LED lamps are positionedand oriented in a suitable arrangement to emit as much radiant power outof the lamp cavity and onto the plant materials being irradiated as canbe provided.

Each of the longitudinal light support beams includes a fluid conduitthermally conductively coupled to the base wall for conducting a liquidcooling fluid there through. A cooling system that includes a fluid pumpand a heat exchanger to pump the liquid cooling fluid through all of thefluid conduits thermally conductively coupled to the base wall and tocycle the cooling fluid through the heat exchanger.

The plurality of LED lamps includes a plurality of different LED lamptypes each emitting a different spectral power. Each array of lampsincludes a blue LED lamps having a main spectral power output in aspectral range of 425 to 470 nm, a plurality of red LED lamps having amain spectral power output in a spectral range of 620 to 650 nm, aplurality of deep red LED lamps having a main spectral power output in aspectral range of 660 to 680 nm and a plurality of white LED lampshaving a main spectral power output in a spectral range of 420 to 620nm. Other LED lamp types may also be used to expand the combinedspectral power output to include different spectral power such as anultraviolet LED lamp type having a main spectral power output in aspectral range of 380 to 420 and or an infrared LED lamp type having amain spectral power output in a spectral range of 730 to 770 nm.Generally, the combined spectral power or regions of the spectral powercan be selected to suit the irradiation needs optical absorption ofdifferent horticultural products.

A lamp power module includes a plurality of different DC power sourcesand each DC power source is electrically interfaced to all of the LEDlamps of only one of the plurality of different LED types. An electroniccontroller including a data processor and a memory module operates eachof the different DC power sources independently to vary the radiantpower output of any one of the different LED types. Since all of the LEDlamps of a given LED type is power by a single DC power source,modulating the DC power source output varies the radian power output ofall of the connected LED lamps at the same time to either turn all ofthe LED lamps of a given type completely off, drive all of the lamps formaximum radiant power output or to drive of the lamps at an intermediateradiant power level.

1.5 BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention will best be understood from adetailed description of the invention and example embodiments thereofselected for the purposes of illustration and shown in the accompanyingdrawings in which:

FIG. 1 depicts a non-limiting exemplary schematic diagram of a plantcultivation system that includes a liquid cooled LED irradiation systemaccording to the present invention.

FIG. 2 depicts a non-limiting exemplary schematic diagram of anelectronic controller for operating a liquid cooled LED irradiationsystem according to the present invention.

FIG. 3 depicts a non-limiting exemplary top isometric view of an LEDlighting assembly according to the present invention.

FIG. 4A depicts a non-limiting exemplary transverse section view takenthrough a first embodiment of a light support beam that includes aliquid conduit formed integral with the light support beam according tothe present invention.

FIG. 4B depicts a non-limiting exemplary transverse section view takenthrough a second embodiment of a light support beam that includes acircular liquid conduit attached to the light support beam according tothe present invention.

FIG. 4C depicts a non-limiting exemplary transverse section view takenthrough a second embodiment of a light support beam that includes arectangular liquid conduit attached to the light support beam accordingto the present invention.

FIG. 5 depicts a non-limiting exemplary top schematic view of aplurality of LED lighting assemblies showing a flow pattern of a liquidcooling fluid passing through each of the plurality of LED lightingassemblies according to the present invention.

FIG. 6 depicts a non-limiting exemplary bottom schematic view of arraysof LED lamps with each array including different LED types and with eachLED type electrically interfaced to a different power supply accordingto the present invention.

FIG. 6A depicts a non-limiting exemplary bottom schematic view depictingan LED unit panel according to the present invention.

FIG. 7 depicts a non-limiting exemplary bottom schematic view of aplurality of LED unit panels and a non-limiting exemplary wiring diagramfor connecting each LED type to a different DC power source.

FIG. 8 depicts a graphical plot showing the relative absorptioncharacteristics of plant material vs wavelength in nm as well as therelative spectral power of a conventional HPS lamp vs wavelength in nm.

FIG. 9 depicts a graphical plot of the relative absorptioncharacteristics of plant material vs wavelength in nm as well as therelative spectral power of a non-limiting exemplary LED illuminationsystem of the present invention vs wavelength in nm.

1.6 ITEM NUMBER LIST

The following item numbers are used throughout, unless specificallyindicated otherwise.

# DESCRIPTION 100 Plant cultivation system 105 Roof 110 Walls 115Climate control 120 Horticultural products 125 Containers 130 Lightingassembly 135 Pump 140 Cooling fluid reservoir 145 Cold side liquidconduit 150 Hot side liquid conduit 155 First heat exchanger 160 Secondheat exchanger 165 Cooling coil 170 Fan 200 Electronic controller 205Data processor 210 Memory module 215 1^(st) Network interface device 2202^(nd) Network interface device 225 Power input port 230 Communicationports 235 Lighting assembly port 240 External power source 250 Powerconditioning and distribution module 255 Battery 260 Sensors 265 Userinterface 300 Lighting assembly 310 Light support beam 315 Light supportbeam 320 Light support beam 325 Light support beam 330 Transverse endbeam 335 Transverse end beam 340 DC power source module 345 DC powersource module 350 End cap 355 Coordinate axes 400 U-shaped cross-section405 Base wall 410 Side wall 415 Side wall 420 Lamp cavity 425 Lightingmodule 430 Support structure 435 LED lamp 440 Reflector surface 445Reflector surface 450 Lamp cavity cover 455 Annular wall 460 Fluidconduit 465 Reflective base surface 470 Top surface 475 Bottom surface480 Circular pipe 485 Rectangular pipe 490 Thermally conductive layer495 Electrically insulating layer 497 Mounting pad 498 Thermallyinsulating layer 500 Cooling flow diagram 505 Cold side liquid conduit510 Hot side liquid conduit 515 Transverse conduit 520 Transverseconduit 525 Transverse conduit 530 Longitudinal conduit 535 Longitudinalconduit 540 Longitudinal conduit 545 Longitudinal conduit 550 Inputconnecting conduit 555 Output connecting conduit 600 LED illuminationsystem 605 LED lamp assembly 610 LED lamp assembly 615 LED lamp assembly620 LED lamp assembly 625 Lamp power module 630 LED unit panel 635 LEDlamp 640 Support structure 645 Power bus 650 DC power source 700 Wiringdiagram 705 Output terminal 710 Red Power source 715 Red conductivetrace 720 Jumper 725 Jumper 730 Jumper 735 Negative terminal 740 Whitepower source 745 Positive terminal 750 Negative terminal 755 Whiteconductive trace 760 Deep red power source 765 Positive terminal 770Negative terminal 775 Deep red conductive trace 785 Positive terminal780 Blue power source 790 Negative terminal 795 Blue conductive trace800 Graphical comparison 805 First curve 810 Second curve 815 Thirdcurve 820 Forth curve 830 Three minor spectral peaks 835 Tail of mainspectral peak 905 Chlorophyll A 910 Chlorophyll B 915 Carotenoids

DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION 1.6.1 System Overview

Referring now to FIG. 1, a non-limiting exemplary plant cultivationsystem (100) according to the present invention is operable to irradiatevarious horticultural products with artificial light. The plantcultivation system (100) is installed inside a structure that at leastincludes a roof (105) and may also include side walls (110). A climatecontrol system (115) is optionally provided to control temperature,humidity, ventilation or the like within the structure as required toprovide an appropriate environment for the various horticulturalproducts.

The various horticultural products (120) are supported in a mannersuitable for cultivation, which may vary widely depending on the type ofhorticultural products (120) and the stage of plant development. In onenon-limiting embodiment, the horticultural products (120) are planted insoil beds and or in soil filled containers (125). In other non-limitingembodiment, the horticultural products (120) are grown without soil inhydroponic beds and or containers (125) that are configured to irrigatethe horticultural products with a suitable static or flowing nutrientrich liquid solution. In one non-limiting example embodiment the soil orliquid filled containers (125) are horizontally disposed over a twodimensional area, e.g. resting directly on a floor surface or resting ona raised horizontal surface such as a table or a horizontal shelfstructure, not shown.

At least one lighting assembly (130) is disposed above the twodimensional horizontal horticultural products support area and thelighting assembly (130) is configured to irradiate the horticulturalproducts (120) from above the two dimensional horizontal horticulturalproducts support area. Accordingly, the size and shape of the lightingassembly (130) is substantially matched to the two dimensionalhorizontal horticultural support area and the lighting assemblypositioned over the two dimensional horticultural support area in amanner that allows the lighting assembly (130) to substantiallyuniformly illuminate the entire two dimensional horizontal horticulturalproducts support area.

As will be recognized, other horticultural product support arrangementsand corresponding lighting assembly configurations are usable withoutdeviating from the present invention as long as the lighting assembly(130) is disposed in a position with respect to the two dimensionalhorizontal horticultural products support area and configured withappropriate length and width dimensions to substantially uniformlyilluminate the entire area supporting horticultural products. In onenon-limiting exemplary embodiment a single lighting assembly (130) isconfigured with length and width dimensions that are substantiallymatched with length and wide dimensions of the horizontal horticulturalproducts support area. In another non-limiting exemplary two or morelighting assemblies (130) each having the same length and the same widthdimension are installed above horizontal horticultural products supportarea such that an overall length and an overall width dimension of thetwo or more lighting assemblies is matched to the length and widedimensions of the horizontal horticultural products support area. Aswill be further recognized by those skilled in the art, various threedimensional horticultural products support areas are usable with one ormore lighting assemblies (130) positioned to illuminate thehorticultural products without deviating from the present invention.

The plant cultivation system (100) includes a liquid cooling systemoperable to continuously or intermittently cool the lighting assembly(130). The liquid cooling system includes a pump (135) and an associatedcooling fluid reservoir (140) for circulating and storing a coolingfluid. The cooling fluid may comprise water, deionized water, inhibitedglycol and water solution, or a dielectric fluid such as polyalphaolefinwhich is a metallized water solution, or any other suitable coolingfluid.

The liquid cooling system includes an input or cold side liquid conduit(145) that extends from the pump (135) to the lighting assembly (130).As will be further described below, the cooling fluid enters coolingfluid conduits that extend through the lighting assembly (130) and thecooling fluid exits from the cooling fluid conduits that extend throughthe lighting assembly (130) to an output or hot side liquid conduit(150). The hot side liquid conduit (150) extends from the lightingassembly (130) to a first heat exchanger (155). In one non-limitingexemplary embodiment the first heat exchanger (155) is a liquid to gasheat exchanger usable to heat room air by an exchange of thermal energybetween the warmer cooling fluid with the cooler room air or other gasas may be desirable. In this case the first heat exchanger (155)includes a fan, not shown, operable to direct a flow of room air overthe liquid to gas heat exchanger element to exchange thermal energybetween the warm cooling fluid and the room air. In another non-limitingexemplary embodiment, the first heat exchanger (155) is a liquid toliquid heat exchanger usable to heat another liquid by an exchange ofthermal energy between the warmer cooling fluid with the second liquidwhich is cooler than the cooling fluid. In this case the second liquidmay comprise the static or flowing nutrient rich liquid solution usableto irrigate the plant containers or hydroponic beds (125) or the secondliquid may be otherwise utilized after heating, e.g. to warm the roomair.

The hot side liquid conduit (150) further extends from the first heatexchanger (155) to a second heat exchanger (160) which may be disposedinside or outside the structure. The cold side liquid conduit (145)further extends from the second heat exchanger (160) to the pump (135).In one non-limiting example embodiment, second heat exchanger (160)comprises a cooling coil (165), or the like, and an air moving device,such as a fan (170). The second heat exchanger (160) provides sufficientcooling capacity to extract enough thermal energy from the cooling fluidto render the cooling fluid ready to cool the lighting assembly (130).If a desired operating temperature of the lighting assembly (130) is notto exceed 140° F. or 60° C., the cooling fluid exiting the second heatexchanger (160) would preferably have a temperature of less than about125° F. or 52° C.

As will be recognized by those skilled in the art the cooling capacityand rate of cooling of the second heat exchanger (160) depends on thesurface area of the cooling coil (165), the temperature gradient betweenthe ambient air being flowed over the cooling coil (165) by the fan(170) and the flow rate of both the cooling fluid, e.g. in liters perminute, and the flow rate of the air being flowed over the cooling coil(165), e.g. cubic centimeters per minute. As will be further recognizedthe flow rate of the cooling fluid can be varied by altering the fluidflow rate of the pump (135) and the flow rate of the ambient air can bevaried by altering the fluid flow rate of the fan (170). Similarly, thecooling capacity and rate of cooling of the cooling fluid usable to coolthe lighting assembly (130) depends on the surface area of the coolingconduits passing through the lighting assembly, described below, thetemperature gradient between the cooling fluid and the surfaces beingcooled by the cooling fluid and the volume flow rate of the coolingfluid, e.g. in liters per minute, being pumped through the lightingassembly (130).

The liquid cooling system further includes various control and sensorelements, not shown. The control elements include various valves, flowrestrictors, or the like, usable to change the flow configuration, e.g.to bypass the first heat exchanger (155) to use only the second heatexchanger (160); or, to bypass the second heat exchanger (160) to useonly the first heat exchanger (155). The control elements may beoperated manually or may be electrically or pneumatically actuated underthe control of an electronic controller (200) shown in FIG. 2.Additionally, the cooling system includes various sensors, not shown,operable to sense temperature, e.g. indoor and outdoor air temperature,temperature of one or more regions of the lighting assembly (130) andtemperature of the cooling fluid and or temperature of the conduitscarrying the cooling fluid such as in one or both of the heat exchangers(155) and (160), on the cold side liquid conduit (145) and or in the hotside liquid conduit (150). Other sensors may also be provided incommunication with the electronic controller (200) to sense coolingfluid pressure and flow rate and or air pressure and flow rate proximateto either of the heat exchangers.

1.6.2 Electronic Controller

Referring now to FIGS. 1 and 2, in a non-limiting exemplary embodiment,the plant cultivation system (100) further includes an electroniccontroller (200). The electronic controller (200) includes a digitaldata processor (205), or other logic controller, a digital memory module(210) in communication with the digital data processor (205), and one ormore wireless and or wired network interface devices (215) and (220)each in communication with the digital data processor (205) and a userinterface device (265) in communication with the data processor (205).The data processor (205) runs an operating program that performs variouslogical operations in order to provide basic command and controlfunctions such as communicating with other electronic devices, powerdistribution, storing data on and retrieving data from the memory module(210), responding to user commands received from the user interfacedevice (265) and operating the user interface device to display orotherwise convey useful information to a user.

In one non-limiting example embodiment, the electronic controller (200)includes a first network interface device (215) such as a wired networkinterface device operating as an Ethernet network interface device usingthe IEEE 802.3 protocol, or the like. Additionally, the electroniccontroller (200) includes a second network interface device (220)operating as a wireless networking interface device such as a cellularnetwork interface device using any one of the GSM, 3G, LTE, 4G cellularnetwork interface protocols, or such as a Wi-Fi network interface deviceusing the IEEE 802.11 network interface protocol or the like. Each ofthe first network interface device (215) and the second networkinterface (220) is in communication with the data processor (205).Alternately one or both of the network interface devices can beincorporated within the data processor (205).

The electronic controller (200) further includes Input Output (I/O)interface elements that at least includes a power input port (225) andmay include a plurality of serial or parallel communication ports (230),e.g. Universal Serial Bus (USB) ports, or the like, and a lightingassembly interface port (235) for interfacing with the lighting assembly(130). Each of the ports (230) and (235) includes a communicationinterface with the data processor (205). The power input port (225)interfaces with an external power source (240) such as grid power. Apower conditioning and distribution module (250) receives input powerfrom the power source (240) and conditions and distributes the power tovarious modules of the electronic controller (200). A battery (255) orother energy storage element is also provided to at least power theelectronic controller (200) when grid power is unavailable.Additionally, the power conditioning and distribution module (250) mayinterface with each of the fan (170), the pump (135), the lightingassembly (130) and any sensors (260) operating on the plant cultivationsystem (100).

The communication ports (230) are interfaced with the data processor(205) and with a plurality of other electrical devices of the plantcultivation system (100) such as the fan (170), the pump (135), thelighting assembly (130) and any sensors (260) operating on the plantcultivation system (100). Accordingly, the communication ports (230)allow the data processor (205) to receive data and status informationfrom the other electronic devices that are being controlled by the dataprocessor (205) and to send command and control information and or datato the other electrical devices as required to operate the plantcultivation system (100). In an alternate non-limiting embodiment, anyone of or all of the other electrical devices of the plant cultivationsystem (100) such as the fan (170), the pump (135), the lightingassembly (130) and any sensors (260) operating on the plant cultivationsystem (100) as well as the climate control system (115) may bereachable over a wired or wireless network using one or both of thefirst and second network interface devices (215) and (220). Thus, insome embodiments elements such as the fan (170), the pump (135), thelighting assembly (130) and sensors (260) include a network interfacedevice operating thereon such that communication with the data processor(205) is over one or both or the first network interface device (215)and the second network interface device (220) instead of or in additionto being reachable over the communication ports (230) or over thelighting assembly port (235). Thus, in various embodiments command andcontrol information and or data is exchanged between electrical devicesconnect to the electronic controller (200) over a network using networkpackets.

1.6.3 Lighting Assembly Unit

Referring now to FIG. 3 a top isometric view of a non-limiting exemplarylighting assembly (300) according to the present invention includes fourlight support beams (310) (315) (320) (325), two transverse end beams(330) and (335) and two DC power source modules (340) and (345). Each ofthe four light support beams (310) (315) (320) (325) is substantiallyidentical having a longitudinal dimension (L) extending along alongitudinal axis (Y). Each of the two transverse end beams (330) (335)is has a transverse dimension (W) extending along a transverse axis (X).Each of the four light support beams (310) (315) (320) (325) is fixedlyattached to a first transverse end beam (335) at a first end thereof andfixedly attached to a second transverse end beam (330) at a second endthereof. The four light support beams (310) (315) (320) (325) are formedfrom an aluminum alloy or from another metal alloy having a coefficientof thermal conductivity preferably ranging from about 200 to 250 W/m° K.Other metals such as alloys comprising copper, silver and gold areusable to increase the coefficient of thermal conductivity up to about300 W/m° K are usable without deviating from the present invention butat greatly increased cost. Each of the two transverse end beams (330)(335) preferably comprise aluminum; however, the end beams can befabricated from materials having lower coefficients of thermalconductivity such as steel.

The four light support beams (310) (315) (320) (325) are joined togetherwith the two transverse end beams (330) (335) by mechanical fasteners toform a substantially rigid frame that can be suspended above the twodimensional horizontal horticultural support area, described above, andpositioned in a manner that allows the lighting assembly (300) tosubstantially uniformly illuminate the entire two dimensional horizontalhorticultural products support area. In one non-limiting exampleembodiment the lighting assembly (300) is suspended from above such ashung from the roof (105). Alternately the lighting assembly (300) issupported from below such as by legs or other support members, notshown, with the support members disposed between the floor and at leasttwo of the four light support beams or at least two of the twotransverse end beams (330) (335). Alternately the lighting assembly(300) is suspended from a wall (110) or any combination of suspendedfrom the roof and the wall and supported from the floor. Additionally,lighting assemblies (300) can be mechanically interfaced to operate incooperation with other structures including plant racks, plantcontainers, vehicles, storage containers, or the like.

Each of the four light support beams (310) (315) (320) (325) includes afirst end cap (350) disposed between a second end of the light supportbeam (310) and the second transverse end beam (330). A secondsubstantially identical end cap, not shown, is disposed between anopposing first end of the light support beam (310) and the firsttransverse end beam (335). For each of the four support beams (310)(315) (320) (325) an end cap (350) is fixedly attached to each endthereof. As will be further detailed below, each of the four lightsupport beams (310) (315) (320) (325) is substantially identical andeach light support beam comprises an extruded U-shaped aluminum channelcomprising by a base wall and two opposing sidewalls.

Generally, the lighting assembly (300) may be formed using a singlelight support beam (325) and a single DC power source module (340) andthe light support beam (325) can have any practical longitudinal length(L). Otherwise it is more economical to configure the lighting assembly(300) with pairs of light support beam (325) and (320) supporting asingle DC power source module (340). More generally any practical numberof pairs of light support beam (325) and (320) each supporting a singleDC power source module (340) or (345) is usable. The longitudinal length(L) is selected to match the length of the number of repeating LED unitpanels, described below, that will be supported by the light supportbeams. However standard longitudinal lengths (L) of 24, 36, 48 and 96inches (0.6. 0.9, 1.2 and 2.4 meters) are preferred.

1.6.4 Light Support Beams

Referring now to FIG. 4A, in a first non-limiting exemplary embodimentof the present invention each of the light support beams (310) (315)(320) (325) is formed with a U-shaped cross-section (400). Morespecifically FIG. 4A depicts a transverse cross-section of any one ofthe light support beams (310) (315) (320) (325) in the X-Z plane (seecoordinate axes (355) in FIG. 3). The U-shaped cross-section (400)includes a base wall (405) and two opposing sidewalls (410) and (415).Each of the side walls (410) and (415) extend substantially orthogonallyfrom a corresponding left and right edge of the base wall (405). Thebase wall (405) and each of the side walls (410) and (415) form threesides of a lamp cavity (420). The lamp cavity (420) has a rectangularcross-section that extends along the entire longitudinal length (L) ofeach of the light support beams (310) (315) (320) (325). Other lampcavity cross-sections are usable, e.g. square, and trapezoidal, withoutdeviating from the present invention. The lamp cavity (420) is providedto house one or more LED lighting modules (425) attached to an insidesurface of the base wall (405).

An LED lighting module (425), shown in cross-section, includes a supportstructure (430) for supporting a plurality of LED lamps (435) thereon.The support structure (430) is attached to an inside surface of the basewall (405) inside the lamp cavity (420). LED lamps (435) are eachsupported by the support structure (430) and are oriented to directradiation emitted by each LED lamps (435) out of the lamp cavity (420).The support structure (430), further described below, provides anelectrical and mechanical interface for powering and supporting each LEDlamp (435).

The lamp cavity (420) further includes two reflective surfaces (440) and(445). Each reflective surface is disposed to provide a trapezoidalshaped light box configured to reflect radiation emitted by each LEDlamp (435) out of the lamp cavity (420). As such that lamp cavity has alight emitting cone angle defined by the reflective surfaces (440) and(445) which can be configured to direct light exiting from the lampcavity (420) toward the two dimensional horizontal horticultural supportarea positioned below the lighting assembly (300). The reflectivesurfaces (440) and (445) may also extend across a reflective basesurface (465) including between the LED lamps (435). The reflectivesurfaces (440) and (445) may be specular reflective surfaces or diffusereflector surfaces. Each of the two reflective surfaces (440) and (445)extends along the entire longitudinal length (L) of the light supportbeam inside the lamp cavity (420). Each reflective surface may beprovided by applying a reflective layer onto a support element. Oneexample includes a thin film adhesive backed reflective tape or filmavailable from the Scotchlite™ division of 3M™. The support element usedto support the reflective tape or other mirrored surface may be formedby one or more bent sheet metal elements or by a molded or otherwiseformed plastic element, or the like. The support elements used tosupport the reflective tape or other mirrored surface may be a singleelement formed to provide both reflective surfaces (440) and (445) andthe reflective base surface (465) along the entire longitudinal length(L) or the support element may be two or more elements each formed toprovide one of reflective surfaces (440) and (445) and the reflectivebase surface (465).

The lamp cavity (420) includes a transparent or translucent lamp cavitycover (450). The lamp cavity cover (450) is installed to moisture sealthe lamp cavity (420) and to protect the support structure (430) and theLED lamps (435) mounted inside the lamp cavity (420) from mechanicaldamage. A separate lamp cavity cover (450) extends along the entirelongitudinal length (L) of each light support beam (310) (315) (320)(325) and interfaces with an end cap (350) at each end of the lightsupport beams. The lamp cavity cover (450) is sealedly interfaced witheach of the side walls (410) and (415) along the entire longitudinallength (L) of light support beam and is further sealedly interfaced witheach of the end caps (350) in order to substantially moisture and gasseal the lamp cavity (420) as well as protect elements inside the lampcavity from mechanical damage. The lamp cavity cover (450) preferablycomprises an impact resistant plastic, e.g. polycarbonate, or comprisesa structural glass, with suitable optical qualities. The lamp cavitycover (450) is a rectangular element having opposing and substantiallyparallel top (470) and bottom (475) surfaces such that any light emittedby the LED lamps (435) passes through both the top surface (470) and thebottom surface (475) of the lamp cavity cover (450) as it exits the lampcavity (420). In one non-limiting example embodiment, the lamp cavitycover is substantially uniformly transparent over the useful spectralpower range of the LED's such as from 350 to 750 nm and both the top andbottom surfaces (470), (475) of the lamp cavity cover (450) areanti-reflection coated using a broad spectrum (e.g. 350 to 750 nm)anti-reflection coating layer. In another non-limiting exampleembodiment, the lamp cavity cover (450) is formed with asemi-transparent or translucent material. Alternately, the lamp cavitycover is substantially uniformly transparent and a semi-transparent ortranslucent coating layer is formed or otherwise applied onto one orboth of the top and bottom surfaces (470), (475). In either case, thesemi-transparent or translucent nature of the lamp cavity cover isprovided to diffuse radiation as it passes through the lamp cavity cover(450). In still further embodiments, the cavity cover is patterned withtransparent regions and semi-transparent or translucent regions as maybe desired to define the light emitting cone angle of the lamp cavity(420) or to otherwise form a desired light exiting pattern for lightexiting from the lamp cavity (420).

The base wall (405) of the U-shaped cross-section (400) includes anannular wall (455) extending from an outside surface thereof opposed tothe lamp cavity (420). The annular wall (455) encloses a circular fluidconduit (460). The annular wall (455) and the fluid conduit (460) extendalong the entire longitudinal length (L) of each of the light supportbeams (310) (315) (320) (325) and the fluid cavity (460) is open at eachend of the light support bean in order to interface with other coolingfluid conduits in order to provide a flow of cooling fluid passingthrough the fluid cavity (460). Additionally, each end of the annularwall (455) may extend beyond the ends of the lamp cavity (420) andinclude or attach to a fluid conduit fitting suitable for interfacingwith other cooling fluid conduits.

The fluid conduit (460) is provided to transport the above describedliquid cooling fluid there through. As detailed above, the U-shapedcross-section (400) is formed from aluminum and the U-shapedcross-section (400) is preferably formed by extrusion. Moreover, sincethe aluminum has a relatively high coefficient of thermal conductivitypreferably ranging from about 200 to 250 W/m° K the U-shapedcross-section (400) readily absorbs thermal energy emitted by thelighting module (425) and rapidly conducts the absorbed thermal energyto all regions of the U-shaped cross-section (400) to rapidly equalizethe operating temperature of the U-shaped cross-section (400) over theentire mass of the light support beam. Meanwhile when cooling fluid ispumped through the circular fluid conduit (460) thermal energy isabsorbed by the cooling fluid along the full length of the light supportbeam. As a result, the lighting module (425) is actively cooled by thecooling fluid in order to maintain the LED lamps (435) at a desiredoperating temperature, e.g. as less than about 140° F. or 60° C. Morespecifically, each light support beam is configured to thermally conductthermal energy from each of the LED's (435) through the supportstructure (430) and through the base wall (405) to the annular wall(455) for transfer to the cooling fluid passing through the conduit(460).

In alternate embodiments shown in FIGS. 4B, and 4C, a circular pipe(480) or a rectangular pipe (485) may be attached to the U-shapedcross-section (400) to provide a circular fluid conduit formed by thecircular pipe (480) or a rectangular fluid conduit formed by therectangular pipe (485). In one non-limiting exemplary embodiment thecircular pipe (480) is a circular copper or aluminum pipe attached to anoutside surface of the base wall (405) e.g. by pipe clamps, adhesivebonding, soldering, or the like. In another non-limiting exemplaryembodiment, the rectangular pipe (485) is a rectangular copper oraluminum pipe attached to an outside surface of the base wall (405) e.g.by pipe clamps, adhesive bonding, soldering, or the like. In each case amechanical interface between the circular pipe (480) or a rectangularpipe (485) provides sufficient mating surface contact area between thepipe and the base wall (405) to provide enough thermal energy conductionfrom the base wall (405) to the cooling fluid flowing through thecorresponding fluid conduit to meet the cooling load.

1.6.5 Cooling Flow Diagram

Referring now to FIGS. 1-5, a top view of a multi-unit lighting assemblyis depicted with a schematic cooling fluid flow diagram (500) of anon-limiting exemplary embodiment of the present invention. As shown themulti-unit lighting assembly of FIG. 5 includes three lightingassemblies (300) installed in a desired operating position shown in atop view. Each lighting assembly (300) includes four light support beamsassembled with two transverse end beams and two DC power source modulesas shown in FIG. 3. Each of the four light support beams includes alongitudinal cooling fluid conduit (530), (535), (540), (545) extendingalong its longitudinal length as described above and shown in FIG. 4.The cooling fluid flow diagram (500) depicts a cold side liquid conduit(505) in fluid communication with the pump (135) and cooling fluidreservoir (140) shown in FIG. 1. A hot side liquid conduit (510) is influid communication with at least one of the first heat exchanger (155)and the second heat exchanger (160) or both.

In the cooling flow diagram (500) each of the lighting assemblies (300)further includes three transverse conduits (515), (520) and (525)arranged to connect each of the four longitudinal cooling fluid conduits(530), (535), (540), (545) in series. Each of the transverse conduits issupported by one of the transvers end beams e.g. (330) and (335)described above and shown in FIG. 3. Each of the transverse conduits(515), (520) and (525) is in fluid communication with two longitudinalfluid conduits. The longitudinal conduit (530) is in fluid communicationwith the cold side liquid conduit (505) over an input connecting conduit(550). The longitudinal conduit (545) is in fluid communication with thehot side liquid conduit (510) over an output connecting conduit (555).

The cooling fluid flowing into the longitudinal conduit (530) from thecold side liquid conduit (505) flows through the longitudinal conduit(530), across the transverse conduit (515), through the longitudinalconduit (535), across the transvers conduit (520), through thelongitudinal conduit (540), across the transvers conduit (525), throughthe longitudinal conduit (545) and out of the lighting assembly (300)over an output connecting conduit (555). In another non-limitingexemplary embodiment, the four longitudinal cooling fluid conduits(530), (535), (540), (545) can be connected in parallel wherein eachlongitudinal cooling fluid conduit receives the cooling fluid from thecold side liquid conduit (505) and returns cooling fluid to the hot sideliquid conduit (510). In a further parallel flow arrangement each pairof two longitudinal cooling fluid conduits e.g. the pair (530), (535),are connected to the cooling fluid system in parallel wherein thelongitudinal cooling fluid conduit (530) is connected to and receivescooling fluid from the cold side liquid conduit (505), and thelongitudinal cooling fluid conduit (535) is connected to and deliverscooling fluid to the hot side liquid conduit (510).

Other elements of the cooling flow diagram (500), not shown, include oneor more fluid control valves disposed along the cold side liquid conduit(505) and the hot side liquid conduit (510) as may be required tooperate one lighting assembly or two or more lighting assemblies byopening and closing control valves. Other fluid control elements orsensors, not shown, may include a pressure sensor, flow rate sensor andor temperature sensors disposed to monitor local temperature and fluidflow conditions as may be required to manage the operating mode of theoverall cooling system and to maintain a desired operating temperature.

1.6.6 LED System

Referring now to FIG. 6 a non-limiting exemplary LED illumination system(600) is shown in a bottom schematic view according to the presentinvention. The LED illumination system (600) includes four LED lampassemblies (605), (610), (615) and (620). Each of the four LED lampassemblies (605), (610), (615) and (620) is directly electricallyinterfaced with a lamp power module (625) or is indirectly electricallyinterfaced to the lamp power module (625) through another LED lampassembly, as is shown in the present example embodiment.

Each LED lamp assembly (605), (610), (615) (620) is attached to adifferent one of the light support beams shown in FIG. 3. For example,the LED lamp assembly (605) is attached to a bottom side of the lightsupport beam (325) shown in FIG. 3 and is attached to the base wall ofthe U-shaped cross-section (400) inside the lamp cavity (420) of thelight support beam (325), as shown in FIG. 4. Likewise, each of theother LED lamp assemblies (610), (615) and (620) is mounted onto thebase wall of the U-shaped cross-section (400), inside the lamp cavity(420), of one of the other light support beams (315), (320) and (325)respectively. Each of the four LED lamp assemblies (605), (610), (615)and (620) is substantially identical and includes seven LED unit panels(630) with each unit panel (630) being substantially identical.

Referring now to FIG. 6A, each unit panel (630) includes a total offourteen (14) LED lamps (635) with each LED lamp (635) comprising alight emitting diode mounted onto a support structure (640) such as aprinted circuit board (PCB) or the like that includes an electricalpower interface to each LED lamp (635) formed thereon. The fourteen LEDlamps (635) are arranged in two side by side rows of seven (7) LED'sformed as seven side by side pairs of two identical LED lamps (635). Theseven pairs of LED lamps include four different LED types wherein eachlamp type has a different spectral power output. In the present exampleembodiments, the seven pairs of LED lamps include a single pair of whiteLED lamps (W), two pairs of blue LED lamps (B), two pairs of red LEDlamps (R) and two pairs of deep red LED lamps (DR) wherein the color ofeach LED type (W, B, R, DR) relates to a characteristic spectral poweremitted by each different LED type. While the seven pairs of LED lampsshown in FIG. 6A is ordered from left to right, blue (B), red (R), deepred (DR), white (W), blue (B), red (R) and deep red (DR) the order ofthe different LED types can be rearranged without deviating from thepresent invention, provided that all like LED types can be powered onand off separately from all other like LED types.

While the arrangement of the unit panel (630) is a preferred embodiment,other arrangements for providing lamp assemblies (605), (610), (615) and(620) can be used without deviating from the present invention. Thetotal number of LED lamps (635) used to provide a unit panel, theposition of each LED lamp (635) on the unit panel and the combination ofLED types and the number of LED lamps per LED type are all variablesthat can be altered to optimize the spectral power output and spatialirradiance pattern of the lamp assemblies for cultivating a particularhorticultural product.

Each unit panel (630) may comprise an individual module e.g. having itsown support structure (640) and having an identical LED lamp arrangementsuch that each unit panel (630) is interchangeable with any other unitpanel (630). Individual unit panels have an advantage that each unitpanel (630) is independently removable from its support beam and can bereplaced by another unit panel in the event that one or more LED lampsof a given unit panel fails or becomes damaged. Alternately, each of thelamp assemblies (605), (610), (615) and (620) is formable using a singlesupport structure (640) that extends along the full length of itscorresponding support beam without deviating from the present invention.

Thus, the exemplary LED illumination system (600) includes four LED lampassemblies (605), (610), (615) with each LED lamp assembly includingseven unit panels (605) with each lamp assembly having ninety eight (98)LED lamps (635) with the four LED lamp assemblies including a total ofthree hundred and ninety two (392) LED lamps (635).

Referring now to FIGS. 1, 2 and 6, according to a non-limiting exemplaryembodiment of the present invention, each like LED lamp type iselectrically interfaced with a dedicated DC power source. The lamp powermodule (625) includes four separately controllable DC power sources witha first DC power source (650R) provided to separately power only red LEDlamps (R), a second DC power source (650DR) provided to separately poweronly deep red LED lamps (DR), a third DC power source (650B) provided toseparately power only blue LED lamps (B) and a fourth DC power source(650W) provided to separately power only white LED lamps (W). Each DCpower source is electrically interfaced with the power conditioning anddistribution module (250) which receives AC grid power and converts theAC grid power to an appropriate DC voltage and current amplitude anddistributes the converted power to various devices including each of theLED lamp DC power sources (650R), (650DR), (650B) and (650W).Alternately, AC grid power may be distributed to each of the LED lamp DCpower sources (650R), (650DR), (650B) and (650W) and each DC powersource includes an AC to DC power converter operating thereon to convertAC grid power to DC power usable to drive LED radiant power output. Inaddition, each LED lamp power source (650R), (650DR), (650B) and (650W)is electrically interfaced to the data processor (205) over the lightingassembly port (235) and is controllable to separately modulate radiantpower output to each different LED type over a radiant power amplituderange of substantially zero radiant power to a maximum radiant amplitudeof the LED lamps being powered.

As will be further recognized by those skilled in the art, the powerconditioning and distribution module (250) may comprise an AC to DCpower converter operable with a linear power regulator, or the like, tooutput substantially constant DC power amplitude at a substantiallyconstant DC voltage to a DC power bus (645). In this case, each of theDC power sources (650R), (650DR), (650B) and (650W) is connected to a DCpower bus (645) with each power source having the same DC voltage andpower amplitude at a power input side. Thus in one non-limiting exampleembodiment, each DC power source (650R), (650DR), (650B) and (650W)comprises a switching power supply using digital pulse width modulationto drive each DC power source to generated a desired DC power output andthe desired power output is based on individual control signals each bya different one of the DC power supplies from the digital data processor(205) over the lighting assembly port (235) such that the DC poweroutput of each DC power supply (650R), (650DR), (650B) and (650W)separately controlled. Alternately each of the DC power sources (650R),(650DR), (650B) and (650W) may comprise any type of current modulatorcontrollable by the data processor (205) to drive the DC power source ata desired DC power output. Generally, the DC power output of each DCpower source is controllable over an amplitude range of substantiallyzero power output and 100% of a desired maximum power output wherein theDC power output range correlates with desired radiant amplitude outputof the LED lamps being powered thereby.

Every red LED (R) in the LED illumination system (600) is electricallyinterfaced to the red power source (650R) and the data processor (205)is operable to modulate the electrical power amplitude being output bythe red power source (650R) over a substantially linear range. Since theelectrical power amplitude output by the red power source (650R) drivesthe radiant power output of each of the red LED's (R), the electricalpower amplitude is modulated in a manner that drives each red LED (R) toprovide a desired radiant power output that ranges between one hundredpercent or a maximum radiant power output and a substantially zeroradiant power output or to output selected radiant power output levelsbetween zero and maximum radiant power output of the red LED's (R).

The arrangement is the same for the other LED types wherein every deepred LED (DR) in the LED illumination system (600) is electricallyinterfaced to the deep red power source (650DR), every blue LED (B) inthe LED illumination system (600) is electrically interfaced to the bluepower source (650B) and every white LED (W) in the LED illuminationsystem (600) is electrically interfaced to the white power source(650W). Thus, according to the present invention, the data processor(205) can be operated to separately modulate the electrical output poweramplitude each power source (650R), (650DR), (650B) and (650W). As aresult, all of the LED lamps of a particular type can be collectivelyoperated at a selected radiant power amplitude ranging fromsubstantially zero to 100% of a desired maximum radiant power amplitudeof a given LED lamp type.

Referring now to FIGS. 6 and 7, a non-limiting exemplary schematicdiagram shows how each LED lamp is serially connected to itscorresponding power source (650R), (650DR), (650B) or (650W). A firstexample wiring diagram (700 a) includes two LED unit panels (630 a) and(630 b) connected in series. A positive power output terminal (705) ofthe red power source (710) is connected in series to each red LED lamp(R) mounted on the two LED unit panels (630 a) and (630 b). A redconductive trace (715) associated with red LED lamps (R) is provided oneach LED unit panel. The red conductive trace (715) is connected to thepositive power terminal (705) and connects with each red LED of a firstpair of red LED's (R) and then connects with each red LED of a secondpair of red LED's (R) where both pairs being mounted on the first LEDunit panel (630 a). A red conductive trace (715) is also formed on thesecond LED unit panel (630 b) and connects with each red LED of a firstpair of red LED's (R) mounted on the second LED unit panel (630 b) andthen connects with each red LED of a second pair of red LED's (R)mounted on the second LED unit panels (630 b). The red conductive trace(715) may comprise a metalized trace formed onto an exposed surface ofthe support structure (640) used to support the LED lamps thereon, orthe red conductive trance (715) may be formed entirely or partially ontointernal layer surfaces of the support structure (640). When each of theLED lamp assemblies comprises a single support structure (640) the redconductive trace (715) connect all of the red LED lamps (R) in serieswith the positive terminal (705). When each of the LED lamp assemblies(605), (610), (615) or (620) is formed by a plurality of substratesupport structures (640), e.g. unit panels (630 a) and (630 b), the redconductive traces of each individual unit panel are electricallyinterconnected in series by one or more together by jumpers (712) atbreaks between adjacent substrate support structures (640).

In a similar manner each of the other LED lamp assemblies (610), (615)or (620) includes a red conductive trace (715) and in some cases jumpers(712) to electrically interconnect all of the red LED lamps (R) inseries. To electrically interconnect all of the red LED lamps (R)mounted on all of four LED lamp assemblies (605), (610), (615) and (620)the red conductive traces (715) of each LED lamp assembly are connectedin series by additional jumpers (720), (725) and (730). At the exit ofthe fourth LED lamp assembly (620) the red conductive trace (715)connects with a negative terminal (735) of the red power source (710)such as by a jumper, or the like.

Similarly, a white power source (740) includes a positive power terminal(745) and a negative power terminal (750). The positive power terminal(745) of the white power source (740) is serially connected to eachwhite LED lamp (W) mounted on the two LED unit panels (630 a) and (630b) by a white conductive trace (755). As described above as related tothe red conductive trace, each unit panel (630 a) and (630 b) includes awhite conductive trace (755) that electrically interconnects each of thewhite LED's (W) mounted on the LED unit panel (630) in series. Similarlyas described above, the white conductive trace (755) in combination withjumpers (712), (720) (725) and (730) interconnect the white conductivetraces (755) in order to electrically interconnect all of the whiteLED's (W) mounted on the LED illumination system (600) in series betweenthe positive terminal (745) and the negative terminal (750) of the whitepower source (740).

As is further shown in an example wiring diagram (700 b), a deep redpower source (760) includes a positive power terminal (765) and anegative power terminal (770). The positive power terminal (765) of thedeep red power source (760) is connected in series to each deep LED lamp(DR) mounted on the two LED unit panels (630 a) and (630 b) by a deepred conductive trace (775). As described above as related to the red andwhite conductive traces, each unit panel (630 a) and (630 b) includes adeep red conductive trace (775) that electrically interconnects each ofthe deep red LED's (DR) mounted on the first LED unit panel (630 a) inseries. Similarly, as described above, the deep red conductive trace(775) in combination with jumpers (712), (720) (725) and (730)interconnect the deep red conductive traces (775) in order toelectrically interconnect all of the deep red LED's (DR) in the LEDillumination system (600) in series between the positive terminal (765)and the negative terminal (770) of the deep red power source (760).

As is further shown in the example wiring diagram (700 b), a blue powersource (780) includes a positive power terminal (785) and a negativepower terminal (790). The positive power terminal (785) of the bluepower source (780) is connected in series to each blue LED lamp (B)mounted on the two LED unit panels (630 a) and (630 b) by a blueconductive trace (795) extends from the positive power terminal (785) tothe first LED unit panel (630 a) and the trace (795). As described aboveas related to the red, white and deep red conductive traces, each unitpanel (630 a) and (630 b) includes a blue conductive trace (795) thatelectrically interconnects each of the blue LED's (B) mounted on thefirst LED unit panel (630 a) in series. Similarly, as described above,the blue conductive trace (795) in combination with jumpers (712), (720)(725) and (730) extends to every blue LED (B) in the LED illuminationsystem (600) in series between the positive terminal (785) and thenegative terminal (790) of the blue power source (780).

In an alternate electrical connecting scheme each of the LED lampassemblies (605), (610), (615) and (620) is connected in parallel withthe four power sources (650R), (650DR), (650B) and (650W). Refereeing toFIG. 6, the traces (720), (725) and (730) are not present. Instead, allfour LED lamp assemblies (605), (610), (615) and (620) are directlyconnected to positive and negative terminal of each all four powersources (650R), (650DR), (650B) and (650W). More specifically for eachlamp assembly, all of the red LED's are connected in series between thepositive and negative terminals of the red power source (650R).Similarly, for each lamp assembly the deep red, white and blue LED'sentire are connected in series between the positive and negativeterminals of the appropriate deep red, white and blue power sources(650DR), (650B), (650W).

Refereeing now to FIGS. 3 and 6, the lamp power module (625) includesall four power sources (650R), (650DR), (650B) and (650W). However, inFIG. 3, two DC power modules (340) and (345) are supported by thetransvers end beams (330) and (335). While it is desirable to supportthe two DC power modules (330) and (335) as shown in FIG. 3, each DCpower module of figure three only includes two of the four power sources(650R), (650DR), (650B) and (650W). Thus, in an embodiment where thelighting assembly (300) was configured with only two light support beamse.g. (310) and (315) using a single DC power module (345), the powermodule (345) would require all four power sources (650R), (650DR),(650B) and (650W).

1.6.7 Thermal Energy Management

Referring again to FIG. 4A, the support structure (430) is configured tofacilitate rapid thermal energy transfer by thermal conduction from eachof the LED lamps (435) to the base wall (405). Additionally, the basewall (405) is configured to facilitate rapid thermal energy transfer bythermal conduction from the support structure (430) to the cooling fluidflowing through the fluid conduit (460). Moreover, in order to providethe conductive traces (715), (755), (775) and (795) to deliver power toeach of the LED lamps (435) the support structure (430) is configured toprovide a PCB layer, or the like, for supporting the conductive traces.

More specifically the support structure (430) includes a thermallyconductive layer (490) and an electrically insulating layer (495). Thethermally conductive layer comprises aluminum, or other metal, having acoefficient of thermal conductivity preferably ranging from about 200 to250 W/m° K. Other metals such as alloys comprising copper, silver andgold are also usable to increase the coefficient of thermal conductivityin a range of 100 W/m° K to 300 W/m° K. The thermal conductive layer(490) is in mating contact with each of the LED lamps (435) in order toprovide a substantially uninterrupted thermal conductive path from eachLED lamp to the fluid conduit (460), As such the thermally conductivelayer (490) may include mounting pads (497) extending therefrom to makemating contact each of the LED lamps (435). During assembly, thermallyconductive grease or another thermally conductive fluid may be appliedto mating surface to improve thermal conduction. Additionally, since theelectrically insulating layer (495) is significantly less thermallyconductive than the thermal conductive layer (490) this prevent thermalenergy from radiating from the thermal conductive layer (490) into thelamp cavity to reduce local heating. Additionally, some or all of theexposed surfaces of the U-shaped cross-section (400) with the exceptionof the inside surface of the base wall (405) that the support structure(430) is mounted onto is coated or otherwise covered by a thermallyinsulating material (498). The thermally insulating layer (498) reducesthermal radiation from the U-shaped cross-section (400) to thesurrounding room air while promoting thermal cooling by thermalconduction to the cooling fluid flowing through the fluid conduit (460).

Referring now to FIG. 9 a plot (900) shows the relative or normalizedspectral power vs wavelength in (nm) of each of the blue LED lamps (B),the white LED lamps (W), the red LED lamps (R) and the deep red LEDlamps (DR) used to configure the LED illumination system (600) of thepresent invention. As shown, the spectral power of the blue LED lamps(B) is centered at about 448 nm with a half width of its bandwidthranging from about 425 to 470 nm. The spectral power of the white LEDlamps (W) has two peaks with a major peak centered at about 450 nm and aminor peak centered at about 570 nm. The half width bandwidth of thewhite LED lamps (W) roughly ranges from about 420 to 620 nm. Thespectral power of the red LED lamps (R) is centered at about 635 nm witha half width of its bandwidth ranging from about 620 to 650 nm. Thespectral power of the deep red LED lamps (DR) is centered at about 670nm with a half width of its bandwidth ranging from about 660 to 680 nm.

In addition to the above described LED illumination systems (600), analternate embodiment of the present invention includes an LEDillumination system that also includes ultraviolet LED lamps having aspectral power with a peak wavelength at about 400 nm and a separateultraviolet power source.

In addition, to above described LED illumination systems (600), afurther alternate embodiment of the present invention includes an LEDillumination system that also includes infrared LED lamps having aspectral power with a peak wavelength at about 750 nm and a separateinfrared power source.

The plot (900) further shows the spectral absorption of plant materialvs wavelength in (nm). The spectral absorption of chlorophyll A (905),chlorophyll B (910) and carotenoids (915) are each plotted on the samewavelength scale as the spectral power of each of the different LED lamptypes used to configure the LED illumination system (600) of the presentinvention. As can be readily seen the spectral power of the deep red LED(DR) closely matches the deep red absorption peak of the chlorophyll Aabsorption curve (905) at about 670 nm.

As can also be seen, each of the spectral power of the deep red LEDlamps (DR), the red LED lamps (R) and the white LED lamps (W) overlapsthe absorption peak of chlorophyll B, curve (910), at about 460 nm andoverlap the absorption of chlorophyll A, curve (910), at about 430 nm.

As can be further seen, each of the spectral power of the blue LED lamps(B) and the white LED lamps (W) overlaps the absorption of chlorophyllA, curve (905), at about 430 nm and overlaps the absorption ofcarotenoids, curve (915), at about 475 nm.

As can be further seen the spectral power of the white LED lamps (W)overlaps the absorption of carotenoids, curve (915), at about 490 nm.

As compared to the spectral power of a conventional HPS lamp shown by afourth curve (820) in FIG. 8, it is readily apparent that the combinedspectral power of the four different LED types used to configure the LEDillumination system (600) of the present invention provides an improvedirradiance source for cultivating horticultural products because thecombined spectral power of the LED illumination system (600) of thepresent invention is much more closely matched to absorption of plantmaterials. Additionally, since the LED illumination system (600) isconfigured to irradiate plant material only using a combined spectralpower that is matched to the absorption characteristics of plantmaterials the system uses less electrical power.

1.7 EXAMPLE 1

The electrical power used by the LED illumination system (600) of thepresent invention is 950 W total. This power usage can be allocated asfollows; white LED lamps 150 (W), blue LED lamps (B) 320 W, red LEDlamps (R) 240 W and deep red LED lamps (DR) 240 W. In a first growingcycle example operating mode, only white and blue light are operated forthe germination stage. This is possible because during the germinationstage the plants absorb more radiation through carotenoids which areprevalent in the plants roots and stems. Thus, during the germinationstage, the power consumption is (470 W) based on only operating thewhite and blue LED lamps. In a second growing cycle example operatingmode, only the white, red and deep red LED lamps are operated during aflowering stage. This is possible because during the flowering stage theplants absorb more radiation through chlorophyll A and chlorophyll Bwhich are prevalent in green leaves. Thus, during the flowering stage,the power consumption is (630 W) based on only operating the white redand deep red LED lamps.

As compared to conventional lighting systems, such as a HPS lamp, theHPS lamp must be run at all time because there is no way to change itspower spectral output. By comparison tests show that the presentinvention is uses less power to achieve comparable plant growth. Forexample, using only 470 W to irradiate horticultural products during thegermination stage and 630 W to irradiate horticultural products duringthe flowering stage the present provides equal horticultural productdevelopment as compared to using a conventional HPS lamp consuming at1000 W and in some case 2000 W during both growth stages.

1.8 EXAMPLE 2

In an example operating mode, the data processor (205) operates adaylight simulation mode wherein LED operating power is gradually variedover a 24 hour cycle to simulate natural sunlight. In another exampleoperating mode, the data processor (205) can be operated to operatedifferent LED types at different LED operating power levels e.g. bydecreasing the radiant power of all of the white LED's while increasingthe radiant power of all of the deep red LED's, or the like.

It will also be recognized by those skilled in the art that, while theinvention has been described above in terms of preferred embodiments, itis not limited thereto. Various features and aspects of the abovedescribed invention may be used individually or jointly. Further,although the invention has been described in the context of itsimplementation in a particular environment, and for particularapplications (e.g. irradiating horticultural products, those skilled inthe art will recognize that its usefulness is not limited thereto andthat the present invention can be beneficially utilized in any number ofenvironments and implementations where it is desirable to vary thespectral power of a light source to match the absorption characteristicsof a scene being illuminated. Accordingly, the claims set forth belowshould be construed in view of the full breadth and spirit of theinvention as disclosed herein.

1-22. (canceled)
 23. A system for irradiating horticultural productswith artificial light comprising: a lighting support structurecomprising one or more lighting support beams each having a longitudinallength and a transverse width, wherein each lighting support beamincludes a liquid cooling conduit enclosed by a conduit outer wall thatis thermally conductively coupled with the lighting support beam; one ormore LED lamp support structures thermally conductively coupled witheach lighting support beam, wherein each LED lamp support structureincludes a plurality of LED lamp elements thermally conductively coupledwith the LED lamp support structure; and, a cooling conduit assemblycomprising the liquid cooling conduit of each of the one or morelighting support beams fluidly coupled together between a fluid inputport and a fluid output ports.
 24. The system of claim 23 wherein eachlighting support beam and the conduit outer wall corresponding therewithcomprises a material having a thermal conductivity of 100 W/m° K orgreater.
 25. The system of claim 23 wherein the liquid cooling conduitenclosed by the conduit outer wall corresponding with each lightingsupport beam extends along the longitudinal length of the lightingsupport beam.
 26. The system of claim 24 wherein each of the one or morelighting support beams is formed by an extruded U-shaped channeldefining a base wall, extending along the longitudinal length and thetransverse width, and two sidewalls extending from the base wall alongthe longitudinal length at opposing edges of the transverse width. 27.The system of claim 24 wherein each of the one or more lighting supportbeams comprises: a base wall that defines the transverse width and thelongitudinal length; two sidewalls extending from the same side of basewall along the longitudinal length; wherein the base wall and the twoside walls form three sides of a lamp cavity; and, wherein each of theone or more LED lamp support structures is attached to the base wallinside the lamp cavity and oriented to direct radiant power emitted bythe plurality of LED lamp elements supported by the one or more LED lampsupport structures, out of the lamp cavity.
 28. The system of claim 27wherein the liquid cooling conduit formed by the conduit outer wall isoutside the lamp cavity.
 29. The system of claim 28 wherein the liquidfluid conduit enclosed by the conduit outer wall is formed with one of,a circular and a quadrilateral cross-section.
 30. The system of claim 29wherein the one or more lighting support beams each includes: atranslucent cover, sealedly interfaced with each of the side walls tomoisture and gas seal the lamp cavity along a longitudinal lengththereof; a first end cap, disposed at a first end of the lamp cavity andsealedly interfaced with, the base wall, the translucent cover and eachof the two side walls, to moisture and gas seal the first end of thelamp cavity; a second end cap, disposed at a second end of the lampcavity, sealedly interfaced with the base wall, the translucent coverand each of the two side walls, to moisture and gas seal the second endof the lamp cavity.
 31. The system of claim 30 further comprising one ormore mirrored surfaces disposed inside the lamp cavity and oriented toreflect radiant power emitted by any of the plurality of LED lamps thatimpinges onto any one of the one or more mirrored surfaces out of thelamp cavity by the mirrored surface.
 32. The system of claim 23 furthercomprising: a cooling loop comprising, the cooling conduit assembly, acold side liquid conduit coupled to the fluid input port, a hot sideliquid conduit coupled to the fluid output wherein the cold side liquidconduit and the hot side liquid conduit; a fluid pump operated tocirculate the first liquid cooling fluid through each of the cold sideliquid conduit, the liquid cooling assembly, and the hot side liquidconduit and then back to the fluid pump; one or more heat exchangeelements disposed along the hot side liquid conduit between the liquidcooling assembly and the fluid pump, wherein each one or more heatexchange element is configured to transfer thermal energy from the firstliquid cooling fluid to a second cooling fluid and wherein each one ormore heat exchange elements includes a controllable fluid moving devicemoved at different rates of motion to control a flow rate of the secondcooling fluid through the heat exchange element; one or more thermalsensors positioned to sense a temperature corresponding with any one of,the first liquid cooling fluid, at one or more locations, a surface ofthe lighting assembly at one or more locations, and the second liquidcooling fluid at each of the one or more heat exchange elements; one ormore flow rate sensors positioned to sense flow rate corresponding withany one of the first liquid cooling fluid and the second cooling fluid;a cooling system controller in communication with, the fluid pump, eachsecond fluid moving device, each flow rate sensor, and each thermalsensor, wherein the cooling system controller is operated toindependently vary flow rates of the first liquid cooling fluid and thesecond cooling fluid to maintain a desired temperature at a region ofthe lighting assembly.
 33. The system of claim 32 wherein the secondcooling fluid comprises one of a gaseous cooling fluid and a liquidcooling fluid.
 34. The system of claim 32 wherein the cooling systemcontroller is operated to maintain a temperature of the plurality of LEDlamp elements, sensed by a thermal sensor disposed on a surface of thelighting assembly that is thermally conductively coupled to one of thelighting support beams at 60° C. or less.
 35. The system of claim 34wherein the cooling system controller is operated to maintain atemperature difference between the temperature of the plurality of LEDlamp elements and a temperature of the first cooling fluid at an exitfrom the last of the one or more heat exchange elements, wherein thetemperature difference is 8° C. or greater.
 36. The system of claim 32wherein the horticultural products are housed inside a structure andwherein one of the one or more heat exchange elements is, one of,disposed inside the structure and disposed outside the structure.
 37. Asystem for irradiating horticultural products with artificial lightcomprising: a lighting support structure comprising one or more lightingsupport beams; one or more LED unit panels coupled to each of the one ormore lighting support beams; a plurality of individual LED lamps,comprising a plurality of different LED lamp types, coupled with eachLED unit panel, wherein each different LED lamp type is configured toirradiate the horticultural products with a different spectral power; afirst power module comprising a DC power bus operated at substantiallyconstant DC bus voltage to output a substantially constant DC bus poweramplitude; a plurality of second DC power modules electricallyinterfaced with the DC power bus to receive the DC power bus amplitudetherefrom, wherein each second DC power module is independently operatedto output a modulated DC power signal having a modulated power amplitudecorresponding with driving the plurality of individual LED lamps of oneof the plurality of LED lamp types to output a desired radiant poweramplitude; an electrical power interface structure comprising, for eachdifferent LED lamp type, conductive elements electrically interfacedbetween, the plurality of individual LED lamps of one of the pluralityof LED lamp types, and one of the plurality of second DC power modules,wherein each second DC power module is electrically interfaced with theplurality of LED lamps of a different one of the plurality of LED lamptypes; an electronic controller comprising, a digital data processor, amemory module in communication with the digital data processor, and anoperating program operated by the digital data processor to performinglogical operations that provide command and control functions at leastcorresponding with irradiating the horticultural products with a desiredspectral power and at a desired radiant power amplitude; wherein theoperating program operates to, apportion, according to the desiredspectral power, the DC bus power amplitude to one or more of theplurality of LED lamp types, determine, for each second DC power module,a determined modulated power amplitude to be output therefrom to achievethe desired spectral power amplitude of the LED lamp type electricallyinterfaced with the corresponding second DC power module, and configure,each second DC power module to output the desired modulated poweramplitude.
 38. The system of claim 37 wherein each of the one or morelighting support beams has a longitudinal length and a transverse widthand includes a liquid cooling conduit enclosed by a conduit outer wallthat extends along the longitudinal length and that is thermallyconductively coupled with the lighting support beam and wherein each oneor more LED unit panel is thermally conductively coupled with thecorrespond lighting support beam further comprising: a cooling conduitassembly comprising the liquid cooling conduit of each of the one ormore lighting support beams fluidly coupled together between a cold sideliquid conduit and a hot side liquid conduit; a fluid pump operated tocirculate a first liquid cooling fluid through each of the cold sideliquid conduit, the liquid cooling assembly, and the hot side liquidconduit and then back to the fluid pump; one or more heat exchangeelements disposed along the hot side liquid conduit between the liquidcooling assembly and the fluid pump, wherein each one or more heatexchange element is configured to transfer thermal energy from the firstliquid cooling fluid to a second cooling fluid and wherein each one ormore heat exchange elements includes a controllable fluid moving deviceoperated to control a flow rate of the second cooling fluid through theheat exchange element; one or more thermal sensors positioned to sense atemperature corresponding with any one of, the first liquid coolingfluid at one or more locations, a surface of the lighting assembly thatis thermally conductively coupled with one of the unit panels, and thesecond liquid cooling fluid at each of the one or more heat exchangeelements; one or more flow rate sensors positioned to sense flow ratecorresponding any one of the first liquid cooling fluid and the secondcooling fluid; a cooling system controller in communication with, thefluid pump, each second fluid moving device, each flow rate sensor andeach thermal sensor, wherein the cooling system controller is operatedto independently vary flow rates of the first liquid cooling fluid andthe second cooling fluid to maintain a desired temperature at a regionof the lighting assembly.
 39. The system of claim 37 wherein the firstpower module comprises, an AC to DC power converter and a linear powerregulator each operating to maintain the substantially constant DC busvoltage and output the substantially constant DC bus power amplitude.40. The system of claim 37 wherein each of the plurality of second DCpower modules comprises a current modulator operable by the electroniccontroller to modulate power amplitude of the modulated DC power signalusing current modulation.
 41. The lighting assembly of claim 37 whereinthe plurality of different LED lamp types includes: a blue LED typehaving a main spectral power output in a spectral range of 425 to 470 nmdriven by a first of the plurality of second DC power modules; a red LEDtype having a main spectral power output in a spectral range of 620 to650 nm driven by a second of the plurality of second DC power modules;and, a deep red LED type having a main spectral power output in aspectral range of 660 to 680 nm driven by a third of the plurality ofsecond DC power modules.
 42. The lighting assembly of claim 40 whereinthe plurality of different LED lamp types further includes a white LEDtype having a main spectral power output in a spectral range of 420 to700 nm driven by a fourth of the plurality of second DC power modules.43. The lighting assembly of claim 41 wherein the plurality of differentLED lamp types further includes an ultraviolet LED type having a mainspectral power output in a spectral range of 380 to 420 nm driven by afifth of the plurality of second DC power modules.
 44. The lightingassembly of claim 42 wherein the plurality of different LED lamp typesfurther includes an infrared LED type having a main spectral poweroutput in a spectral range of 730 to 770 nm driven by a sixth of theplurality of second DC power modules.
 45. The system of claim 37 whereinplant materials of the horticultural products being irradiated have oneor more spectral absorption peaks and wherein a spectral power output ofat least a portion of the plurality of different LED lamp types ismatched with one or more spectral absorption peaks of the plantmaterials.
 46. The lighting assembly of claim 37 wherein the operatingprogram operates to provide command and control functions correspondingwith irradiating the horticultural products with a different spectralpower during different growth stages of the horticultural products. 47.The lighting assembly of claim 37 wherein the operating program operatesto provide command and control functions corresponding with irradiatingthe horticultural products with one of, a fixed spectral power, whiletemporally varying a radiant power amplitude of the irradiation over atemporal radiant power cycle, and with a fixed radiant power amplitude,while temporally varying a spectral power amplitude of the irradiationover a temporal spectral power cycle.
 48. A method for irradiatinghorticultural products with artificial light comprising the steps of:supporting, by a lighting support structure, comprising one or morelighting support beams, one or more LED unit panels coupled to each ofthe one or more lighting support beams, wherein each LED unit panelincludes plurality of individual LED lamps comprises a plurality ofdifferent LED lamp types coupled thereto, wherein each different LEDlamp type is configured to irradiate the horticultural products with adifferent spectral power; outputting, by a first DC power modulecomprising a DC power bus, a substantially constant DC bus poweramplitude at a substantially constant DC bus voltage; powering, by theDC power bus, a plurality of second DC power modules electricallyinterfaced with the DC power bus to receive the DC bus power amplitudetherefrom; outputting, from each second DC power module, a modulated DCpower signal at a power amplitude that corresponds with, driving, theplurality of individual LED lamps of one of the plurality of LED lamptypes, to output a desired radiant power amplitude, wherein themodulated DC power amplitude output by each of the plurality of DC powermodules is configured to drive individual LED lamps corresponding withdifferent ones of the plurality of LED lamp types at different poweramplitude levels; distributing, from each second DC power module, to theplurality of individual LED lamps of one of the LED lamp types, themodulated DC power amplitude output thereby, wherein the modulated DCpower amplitude output by each second DC power module is distributed tothe plurality of LED lamps of a different one of the plurality of LEDlamp types; performing, by an operating program operating on anelectronic controller comprising a digital data processor incommunication with a memory, logical operations that provide command andcontrol functions at least corresponding with controlling the first DCpower module and the plurality of second DC power modules to irradiatethe horticultural products with a desired spectral power; apportioning,by the operating program, according to the desired spectral power, aportion of the DC bus power amplitude to one or more of the differentLED lamp types; determining, by the operating program, for each secondDC power module, a determined modulated DC power amplitude valuecorresponding with the apportionment of the DC bus power amplitude tothe LED lamp type corresponding with the second DC power module; and,configuring, by the electronic controller, each second DC power moduleto output the determined modulated DC power amplitude value.
 49. Themethod of claim 48 wherein the step of powering the DC power busincludes, converting an AC power signal, input to the first DC powermodule, to a DC power signal, and regulating the DC voltage and poweramplitude.
 50. The method of claim 49 wherein each of the plurality ofsecond DC power modules comprises a current modulator that isindependently operated by the electronic controller, wherein the currentmodulator operates to current modulate the substantially constant DC buspower amplitude received from the DC power bus and to output thedetermined modulated DC power amplitude value corresponding with theapportionment of the DC bus power amplitude to the LED lamp typecorresponding with the second DC power module.
 51. The method of claim48, wherein plant materials of the horticultural products beingirradiated have one or more spectral absorption peaks, furthercomprising the step of matching a spectral power of least a portion ofthe plurality of different LED lamp types, included on each unit panel,with one or more spectral absorption peaks of plant materials.
 52. Themethod of claim 48 wherein the operating program operates to providecommand and control functions corresponding with irradiating thehorticultural products with different spectral power outputs, furthercomprising the step of irradiating the horticultural products with thedifferent spectral power outputs during different growth stages of thehorticultural products.
 53. The method of claim 48 wherein the operatingprogram operates to provide command and control functions correspondingwith irradiating the horticultural products with different spectralpower outputs and with different radiant power outputs furthercomprising steps of; irradiating the horticultural products with a fixedspectral power while temporally varying a radiant power amplitude of theirradiation; and, irradiating the horticultural products with a fixedradiant power amplitude while temporally varying a spectral poweramplitude.